MEMBRANE CARTRIDGE SYSTEM

• US 20160151744A1
• Filed: 05/20/2014
• Published: 06/02/2016
• Est. Priority Date: 06/12/2013
• Status: Active Grant

• Current Assignee: Evonik Operations GmbH (Rag-Stiftung)
• Original Assignee: Evonik Fibres Gmbh (Rag-Stiftung)
• Inventors: Visser, Tymen, Pedersen, Steven K.
• Granted Patent: US 10,456,750 B2
• Time in Patent Office: Days
• CPC Class Codes: B01D 2313/04 Specific sealing means
• CPC Class Codes: B01D 2313/041 Gaskets or O-rings
• CPC Class Codes: B01D 2313/042 Adhesives or glues
• CPC Class Codes: B01D 2313/21 Specific headers, end caps
• CPC Class Codes: B01D 2313/44 Cartridge types
• CPC Class Codes: B01D 63/022 Encapsulating hollow fibres
• CPC Class Codes: B01D 63/0221 using a mould
• CPC Class Codes: B01D 63/04 comprising multiple hollow fibre assemblies

Abstract

The present invention is related to a new membrane cartridge system comprising hollow fiber membranes, a special new end cap for the production of the new cartridge, membrane separation devices comprising the new membrane cartridges and a process for manufacture of the new cartridges.

Claims

1. A cartridge element comprising a bundle of hollow fiber type membranes aligned in a cartridge tube and end caps at each end of the cartridge tube, wherein

the cartridge tube comprises at least one fluid inlet/outlet opening arranged between the end caps,

the end caps are made of a polymeric material

the end caps are fixed to the cartridge element, and

the tube sheets at each end of the membrane bundle are fixed to the cartridge element.

2. The cartridge element according to claim 1, wherein at least one end cap, preferably both end caps, is/are fixed to the cartridge element by building a multi-layer composite structure which comprises:

a cap layer which is formed by the end cap

a fixing layer between the end cap and the cartridge tube, preferably composed of the same resin also used to form the tube sheet

a tube layer, formed by the cartridge tube, and optionally but preferably

the tube sheet layer, formed by the resin and the fiber bundle.

3. The cartridge element according to claim 2, wherein the cartridge tube comprises at least one opening, arranged in a region where the cartridge tube is covered by the end cap which allows the potting resin to penetrate through the cartridge tube into an hollow space between the outer surface of the cartridge tube and the inner surface of the end cap.

4. The cartridge element according to claim 1, wherein in that at least one end cap, preferably both end caps, is/are partially, i.e. not to the whole length of the end cap, slid onto or into the cartridge tube.

5. The cartridge elements according to claim 4, wherein

the end cap comprises a first part (a) with an inner diameter which is wider than the outer diameter of the cartridge tube or a first part with an outer diameter which is narrower than the inner diameter of the cartridge tube

said first part of the end cap comprises spacers that center the cap onto or into the cartridge tube and leave space between the respective surface of the cartridge tube and the respective surface of the first part of the end cap which can be filled with a resin.

6. The cartridge element according to claim 4, wherein

the end cap comprises a first part (a) with an inner diameter which is wider than the outer diameter of the cartridge tube and a second part (b) with an inner diameter smaller than that of the first part, so that the second part cannot be slid onto the cartridge tube;

or

the end cap comprises a first part (a) with an outer diameter which is smaller than the inner diameter of the cartridge tube and a second part (b) with an outer diameter larger than that of the first part, so that the second part cannot be slid into the cartridge tube.

7. The cartridge element according to claim 4, wherein the end cap comprises a first part (a) which is slid onto the cartridge tube and a third part (c) having a smaller outer diameter compared to the first part,

8. The cartridge element according to claim 1, wherein the cartridge tube is made of a metal, preferably stainless steel or aluminum and/or

has a wall thickness of 0.5 to 10 mm, preferably 0.5 to 8 mm, particular preferred 1 to 5 mm and very particular preferred 1 to 3 mm

and/or

has an inner diameter that is between 10 and 250 mm, preferably between 30 and 150 mm and particular preferred between 50 and 110 mm.

9. The cartridge element according to claim 1, wherein the resin forming the tube sheet and/or forming the fixing layer is selected from the group consisting of epoxy resins or polyurethane resins, preferably of a resin having one, particular preferred at least one, most preferred all of the following properties:

Glass transition temperature >

80°

C., preferably 80°

C. to 250°

C.

Flat sample bars (according to standard test ASTM D648-07) made from the potting resins have a flexural strength >

70 MPa at room temperature

Flat sample bars (according to standard test ASTM D648-07) made from the potting resins have a elongation at break >

8%

it starts curing at temperatures below 40°

C., preferably below 30°

C., most preferred between 15 to 25°

C.,

a fully cured potting made in a mould having an inner diameter of 110 mm and filled with approximately 500 grams of resin and optional fibers has a shrinkage below 0.5%, preferably 0 to 0.3%,

it has a gel time of >

1 hour a viscosity after mixing <

2000 cPs or mPas

if the resin comprises a filler, the filler does not segregate upon centrifuging with 20 to 40 G

12. The cartridge element according to claim 1 or end cap according to claim 10, wherein the end cap is made of a polymer or polymer blend or polymer mixture, which is optionally filled with up to 30% by weight of glass fibers or other reinforcing materials and which is selected from polyphenylene sulfide or a blend of polyphenylene oxid and polystyrene or another polymer or polymer blend or polymer mixture possessing one, preferably at least one, most preferred all, of the following properties:

it is injection mouldable

its maximum thermal expansion coefficient is 1×

10<sup>−

4</sup> 1/K;

very preferred 5×

10<sup>−

5</sup> or lower its heat deflection temperature, i.e. a temperature up to which the material keeps it shape, of at least 140°

C., preferably higher than 140°

C. to 300°

C.

end caps made of the polymer have a shrinkage of less than 1%, preferably less than 0.5%.

13. The membrane separation device comprising a cartridge element according to claim 1.

14. The membrane separation device according to claim 13, comprising in addition

a single or multi cartridge housing

O-rings arranged between each end cap of the cartridge and the cartridge housing to separate feed and permeate atmospheres.

10. An end cap for manufacture of cartridge elements comprising a bundle of hollow fiber type membranes aligned in a cartridge tube wherein

the end cap is made of a polymeric material

the end cap comprises a first (a) and a second part (b), wherein the first part has an inner diameter which is wider than the inner diameter of the second part or wherein, the first part has an outer diameter which is smaller than the outer diameter of the second part, preferably the differences in the diameters are chosen in a manner that the second part cannot be slid onto or into the cartridge tube,

said first part of the end cap optionally comprises spacers that center the cap onto or into the cartridge tube and leave space between the respective surface of the cartridge tube and the respective surface of the first part of the end cap which can be filled with a resin.

11. The end cap according to claim 10, wherein

the end cap comprises a third part (c) which, after the cap is slid onto or into the cartridge tube, extends beyond the end of the membrane bundle and forms a reservoir/container for the potting resin,

and/or

the end cap comprises an inlet for the potting resin that can be connected, for example with hoses to a source of the potting resin

and/or

the end cap comprises at least one marking that shows where the cutting after the potting has to be done.

15. The process for manufacture of hollow fiber cartridge elements comprising the steps

a) providing a bundle of hollow fiber membranes and a cartridge tube, preferably with at least one fluid inlet/outlet opening

b) sliding the membrane bundle into the cartridge tube

c) mounting plastic caps, preferably according to claims 9 to 12, on both sides of the assembly of step b)

d) placing the assembly obtained in step c) into a centrifuge in a manner that ensures that the assembly is hold together

e) filling a potting resin into both end caps and curing during centrifugation

f) cutting off the end parts of both end caps to open the bores of the hollow fiber membranes.

16. The process according to claim 15, wherein it comprises at least one of the following additional steps

placing a porous material, preferably a mesh, between the outer surface of the bundle of hollow fiber membranes and the inner surface of the cartridge tube

closing off the ends of the fibers with wax or an epoxy or polyurethane resin before potting

pre-treating at least those parts of the surface of the end cap that get into contact with the potting resin with a flame or chemically, preferably with an acid, or mechanically, preferably by sand blasting, to purify the surface and optionally to roughen it in order to improve its adhesion/stick to the cartridge element

pre-filling the end caps before centrifugation starts

heating the cartridge before and during cutting off to a temperature above the Tg of the cured potting resin.

17. The process according to claim 15, wherein centrifugation is done at 200 to 350 rpm and at a temperature between 5 and 40°

C.